Breathing apparatus



July 14, 1931. R. H. DAVIS BREATHING APPARATUS Filed Aug. 20, 1929 2:sheets-sneet 1 F' T l I l I l I l l i l l I l I I i l lnvanto'r GM M bwJuly 14, 1931, R. H. DAVIS BREATHING APPARATUS Filed Aug. 20, 1929 2Sheets-Sheet 2 Patented July 14, 1931 auren STATES PATENT OFFICE- ROBERTHENRY DAVIS, or LoNnom'ENeLAND BREATHING APPARATUS Application filedAugust 20, 929, Serial museum, and in Great Britain May 21, 1929.-

This invention relates to breathing apparatus of the kind employing abreathing bag in which a chemical substance is employed to absorbthecarbon dioxide content of the expired breath. of the user of theapparatus, and also having within the bag one or more comparativelysmall and light capsules filled with a respiratory gas, such asoxygen,or

dispense with the use of chemical substances capable of evolving oxygenin the manner described, as it is found that the liberation of theoxygen therefrom is comparatively slow. 7 1

According to the present invention there is provided a breathingapparatus comprising a breathing bag, a canister open to the said bag,and charged with a"che'mical substance which reacts only 'toabso'rbcarbon dioxide, a mouth-piece for the user of the apparatus connected tothe said canister so; that his breath will pass through the latter intothe bag, and at least one capsule charged with respiratory gas, such asoxygen, or air, 'or a mixture of air andoxygen, under pressure,

disposed'within the bag and capable of being unsealed to liberate thegas into the bag.

In a suitable arrangement for carrying the invention into practice, achemical absorbent 40 for carbon dioxide, for instance, soda lime orcaustic soda, or a mixture of both ofsaid substances,is disposed withina canister arranged in communication with amouth-piece and a breathingbag containing the capsule or cap- 4 sules, A cylinder containingcompressed oxygen is arranged outside the said bag and the outlet of thesaid cylinder connected to the said bag by a tube so that by operating asealing valveof the said cylinder a supply 5.0 of oxygen can befurnished to thebag,

which addition to or in place of that furnished by the capsule orcapsules.

The canister may be placed either outside or within the breathing bagand connected'by atube to the mouthpiece. s The breathing bag may alsoadvantageously be fitted with a connection whereby it can be chargedwith respiratory gas such as oxygen from any suitable source of supplyindependently of the capsule or capsules contained'within the said bagand of the oxygen cylinder 3 above referred to.

Thebr'eathing bag may also be fitted with paratus is used ina'p'oisonous atmosphere 1 and of being opened when the apparatus is usedunder waterto allow of the escape of excess gas. v

To enable the invention to be clearly understood, the same will bedescribed with reference to the accompanying drawings, in

a valve capableof being closed when the ap- -Figure 1 isasectional frontelevation of breathing apparatus constructed in accordance with theinvention. Figure 2 is a sectional side elevation of the pparatus, thesection being taken on the line 2-2 of Figure 1, and, p

Figures 3 and 4 are, respectively, a sectional elevation and a plan viewof thecani'ster'for -the chemical absorbent, detached'from theapparatus, I i

Referrmgto the drawings, a 1s a breathing bag made of flexible gas-tightmateriahb is V I a capsule arranged within the bag a,the said if capsulebeing filled with a respiratory gas such 'asoxygen, orair, or a mixtureof oxygen and air, under pressure, and having its outlet 0 sealed with aclosed tube d deslgned to be broken off to allow of the'escape of thecompressed gas into the bag 5a. To enable the breaking of the tube d tobe easily effected,

"it' is furnishedwitha screw-thread," and a fit ting e is arranged toproject through and within the bag a and be secured to a side wall aofthe latter by a nut 'f, the said fitting 'beingformed with ascrew-threaded hole 9 to receive the tube d. If, the'refore'the portionof the fitting'e' exterior to the bag be held by One 11ml f the a a theapp atus, p es;

sure applied on the exterior of the bag by the other hand can be exertedon the capsule and cause rupture of the tube d, to allow the compressedgas in the said capsule to expand into the said bag.

h is a canister containing a chemical capable of reacting only withcarbondioxide, for instance, soda lime, or caustioisoda, or a mixture ofboth said substances, which is coilfined between layers 2', i of wiregauze or the like, the layer 2' being. located adjacent an opening 3' inthe upper end of the canister and the layer 71 fitting within the openlower end it of ee ethe e d. p hihs 1 be ng 1- rounded byan upwardlyprojecting 'rimjy' The sa d ehie e e. a ran e thin he bag a and issecuredtoa portion a? of the ennenweltei he. ee el eget e ep hin y atilPSJJFBQ Z end be ng eehh ted y a lexi tube to -pe eemenwh eh e m untede eee el m T hehh t eh f e a etee e the tu l ehywey 0 hollow fittingairing-e; hhe re teheieh. 0 i the ei tubeis ettaeheet en being u d e teehi -te h b ere th upp r-W l (fiof thebag a being. formed withanopening at a to receive tliQi IiKrjP on the canister and elemped. ehhd. he a d. p ning between he fitt hee ehdithe hiete ee h t .e ee eweerteethe eu e pu po e o ec ri thete e te the ee-is ehiete he e ette ethebea- The portion a of the bag containing the epeh ha i terme e e e te met eLe ,-P hP,. het y tr ing he a pe hes the .e hie ee e. placed n eied fromthe bag.

The. eeh en I iheteed. e e g a an Within h he the eee ibeame be enrangedexterior thereto, with itsv lower .end sewed .te QQ a PQB Il h 'theeeidsh 9 en;eyhhde eh h h e pre xygen, air, or a mixture thereof,arranged. outide. the hes ih peehe r en entexteneien la e 9. 2 the h s ath utle h m th a d l. ;a .l eh.e ha e hhee ed by hhe t e he part of thefitting e which projectsthrough th aid beg.) h per h e the sai fit i gbe n teased ta ule an pe v'i e w h e ereee-n e g a in the part he f eete W h n he ee d e By h eee e em if he eehhsf-va t ef ehde -q h mehiphitee, the. e mpr d ge th n h a cylinder can be, allowed, to expand intothe hash hyye e th t t n he-pa ag u i e tt K a 'llhebaga is alsofittedwith a connection t hs ihelfeh it eeh eleh ed th eep het re. ee .e.h;eee y .n .e1 er t n reeheehr l 'eh tteehe te t e has eta-ed iheleehdeh l et e eiepli ee b he teneteft: heea inder Q schich f ha eeidiheaT i ehhe bn fitt ngs th', te i tw and ep n d ly nt theehehi e eeredrw hhen openthQ Said. breathing erior of; said bag.

' breath ng. bag

ing in the bag a by the nut 00 a non-return valve 7 being arrangedwithin a part 02 screwing on to the said fitting. The said fitting partm is formed with a spigot 00 which is screw-threaded to enable thesupply tube from the source of the compressed gas, not shown, to be.connected thereto, say, by a h i hi'eiht Although the last describedsupply of compressed respiratory gas has been described as beingsuppliedto the bag a by way of the canister h, it is to be understood that itmay be supplied directly to the said bag.

2 is a non-return valve connected to the bag ct and made in the fornr ofa flattened tubeofi rubber, or likeelastic material, having elite e e1he eel e-r e e ee se m; h a d he es het e te P e u which tends toclosethe valve by pressing the flat i e e a t he e th From the foregoing itis to beunderstood that the user of the breathing bag has three separatesources of r espirat )ry gas upon which to rely.

The valye emay be arr angedsothat it can beea sily closed, for exampleby meansv of a tap or clip', if the apparatus be used; in a poisonousatmosphere. Or, instead the f exi le v e h l-fl x b e theturn a y h e pe e t allow e e iee' of het e er e eh e h inery a ein elhp ey d e=e e theh et fie he the apparatus is used. in poisonous, atmosphere.

a? a? and o -a indicate pairs of straps on the bag a for securing. thesaid bag and its fittings in position for use, tl 1e strapso? exehd -nge u eh heneek, e d h r pe around he he y. e h teen a a are a pair ofstraps on the mouthpiece which are secured around the head of the .user.

It; is to be understood that the canister k asshowmpreferably comprisesthe device described in the specification of; the co-pending t shp enpplieatien Ne- 2,3 0, date the 19th. July, 1929.

aims;

A eat ng. appar us, omp i g a breathing bag, a canister containing anabsorbent of carbon dioxide arranged in commu ca ion with aid bre h ngag, a thp e e pe a iv ly eenne edz here e, a cylinder, charged with arespiratory gasfunderp e sure i va ve e ntr dco mu i tion with. saidbreathing bag to furnish the J rma supply f. b ea hi g g to s id bag,and. a l ast on c psule. ha ged. with, a respiratory gas under pressuredisposed within bag'insuch a. position as to ,bebreakable to liberate anemergency. supply of'gas intothe said breathing bagbya wrenchingmovement applied from the ex- 2; A breathing apparatus, comprising a ,acanister containing an absorbent of carbon dioxide arranged incommunication with said breathing bag, a mouthpiece operativelyconnected thereto, a cylinder charged With a respiratory gasunderpressure, a fitment in communication with said breathing bag, a valvefor controlling the flow of the normal supply of breathing gas from saidcylinder to said fitment, and at least one emergency-gas capsule mountedupon said fitment and disposed within the said breathing bag in such aposition as to be breakable to liberate an emer: gency supply of gasinto the said breathing bag by a wrenching movement applied from theexterior of said bag.

3. A breathing apparatus, comprising a breathing bag, a canistercontaining an absorbent of carbon dioxide arranged in communication withsaid breathing bag, a mouthpiece operatively connected thereto, acylinder charged with a respiratory gas under pressure, a fitment incommunication with said breathing bag for controlling the flow of thenormal supply of breathing gas from said cylinder to said fitment, andat least one capsule charged with a respiratory gas under pressuredetachably mounted upon said fitment and disposed within the saidbreathing bag in such a position as to be breakable to liberate anemergency supply of gas into the said breathing bag by a wrenchingmovement applied from the exterior of said bag.

. ROBERT HENRY DAVIS.

